Add support for rendering with "keep aspect ratio" parameter in the C bindings

inc/rlottie_capi.h

@@ -233,6 +233,23 @@ RLOTTIE_API size_t lottie_animation_get_frame_at_pos(const Lottie_Animation *ani
  */
 RLOTTIE_API void lottie_animation_render(Lottie_Animation *animation, size_t frame_num, uint32_t *buffer, size_t width, size_t height, size_t bytes_per_line);
 
+/**
+ *  @brief Request to render the content of the frame @p frame_num to buffer @p buffer.
+ *
+ *  @param[in] animation Animation object.
+ *  @param[in] frame_num the frame number needs to be rendered.
+ *  @param[in] buffer surface buffer use for rendering.
+ *  @param[in] width width of the surface
+ *  @param[in] height height of the surface
+ *  @param[in] bytes_per_line stride of the surface in bytes.
+ *  @param[in] keep_aspect_ratio whether to keep the aspect ratio while scaling the content.
+ *
+ *
+ *  @ingroup Lottie_Animation
+ *  @internal
+ */
+RLOTTIE_API void lottie_animation_render_aspect(Lottie_Animation *animation, size_t frame_num, uint32_t *buffer, size_t width, size_t height, size_t bytes_per_line, int keep_aspect_ratio);
+
 /**
  *  @brief Request to render the content of the frame @p frame_num to buffer @p buffer asynchronously.
  *
@@ -250,6 +267,24 @@ RLOTTIE_API void lottie_animation_render(Lottie_Animation *animation, size_t fra
  */
 RLOTTIE_API void lottie_animation_render_async(Lottie_Animation *animation, size_t frame_num, uint32_t *buffer, size_t width, size_t height, size_t bytes_per_line);
 
+/**
+ *  @brief Request to render the content of the frame @p frame_num to buffer @p buffer asynchronously.
+ *
+ *  @param[in] animation Animation object.
+ *  @param[in] frame_num the frame number needs to be rendered.
+ *  @param[in] buffer surface buffer use for rendering.
+ *  @param[in] width width of the surface
+ *  @param[in] height height of the surface
+ *  @param[in] bytes_per_line stride of the surface in bytes.
+ *  @param[in] keep_aspect_ratio whether to keep the aspect ratio while scaling the content.
+ *
+ *  @note user must call lottie_animation_render_flush() to make sure render is finished.
+ *
+ *  @ingroup Lottie_Animation
+ *  @internal
+ */
+RLOTTIE_API void lottie_animation_render_async_aspect(Lottie_Animation *animation, size_t frame_num, uint32_t *buffer, size_t width, size_t height, size_t bytes_per_line, int keep_aspect_ratio);
+
 /**
  *  @brief Request to finish the current async renderer job for this animation object.
  *  If render is finished then this call returns immidiately.

src/binding/c/lottieanimation_capi.cpp

@@ -168,6 +168,21 @@ lottie_animation_render(Lottie_Animation_S *animation,
     animation->mAnimation->renderSync(frame_number, surface);
 }
 
+RLOTTIE_API void
+lottie_animation_render_aspect(Lottie_Animation_S *animation,
+                        size_t frame_number,
+                        uint32_t *buffer,
+                        size_t width,
+                        size_t height,
+                        size_t bytes_per_line,
+                        int keep_aspect_ratio)
+{
+    if (!animation) return;
+
+    rlottie::Surface surface(buffer, width, height, bytes_per_line);
+    animation->mAnimation->renderSync(frame_number, surface, keep_aspect_ratio);
+}
+
 RLOTTIE_API void
 lottie_animation_render_async(Lottie_Animation_S *animation,
                               size_t frame_number,
@@ -183,6 +198,22 @@ lottie_animation_render_async(Lottie_Animation_S *animation,
     animation->mBufferRef = buffer;
 }
 
+RLOTTIE_API void
+lottie_animation_render_async_aspect(Lottie_Animation_S *animation,
+                              size_t frame_number,
+                              uint32_t *buffer,
+                              size_t width,
+                              size_t height,
+                              size_t bytes_per_line,
+                              int keep_aspect_ratio)
+{
+    if (!animation) return;
+
+    rlottie::Surface surface(buffer, width, height, bytes_per_line);
+    animation->mRenderTask = animation->mAnimation->render(frame_number, surface, keep_aspect_ratio);
+    animation->mBufferRef = buffer;
+}
+
 RLOTTIE_API uint32_t *
 lottie_animation_render_flush(Lottie_Animation_S *animation)
 {